In the related art, a high resolution image (e.g. 1920×720 pixels) may be obtained via mosaicking two low resolution images (e.g. 1280×720 pixels) taken by two cameras. Preparation procedures before capturing the images to be mosaicked may include steps of: taking test images by two cameras; loading the images to a computer; mosaicking the images; determining whether a resolution of a mosaic image meets requirements; and if the resolution of the mosaic image does not meet the requirements, adjusting a relative angle between the two cameras, and repeating the above steps of: taking test images; loading the images to the computer; mosaicking the images; determining whether a resolution of the mosaic image meets the requirements. In some cases, the above steps may have to be repeated several times until the mosaic image meets the requirements, and thus such preparation procedures are complicated and timing consuming.